The extensible Markup Language (XML) is emerging as one of the most important formats for document and data representation and transmission. For example, business documents can be presented by XML for Internet transmission and World Wide Web access. More and more users and new applications are starting to require their input and output to be in XML format.
Details of XML are described in “Extensible Markup Language (XML) 1.0,” W3C Recommendation Feb. 10, 1998, the disclosure of which is incorporated by reference herein. An XML document can be modeled as a tree, see “Document Object Model (DOM) Level 1 Specification, version 1.0,” W3C Recommendation 1 Oct. 1998, the disclosure of which is incorporated by reference herein.
The Electronic Data Interchange (EDI) flat file format has been in use by the auto, health care, manufacturing and other industries, for more than 20 years. Due to the communication cost at the time the format was designed, data is highly compressed based on EDI maps and dictionaries.
The looping problem in structural documents, such as those defined by the Document Object Model (DOM) and extensible Markup Language (XML), can have a remarkable impact on application programming. The problem is that similar data items within a document may repeat several times, and that related data items are not properly grouped together. The problem is most severe in documents represented in flat file format, for example EDI, and there are few or no data grouping tags or position symbols to distinguish the occurrences of loops. Documents with poor data groupings may complicate the code structure of an application program that must read the document, as the programmers may need to write extra code to sort out the repeating data items and loops. In certain applications, such as XSL, the XML Stylesheet Language, “XSL Transformations (XSLT) 1.0,” W3C Recommendation 16 Nov. 1999, this becomes difficult since the allowable structural construct and formatting style may be limited.